After activate debuglog module and restart Icinga
No more information
[2023-02-05 15:35:05 +0100] information/ApiListener: New client connection from [::ffff:127.0.0.1]:60712 (no client certificate)
[2023-02-05 15:35:05 +0100] notice/ApiListener: New HTTP client
[2023-02-05 15:35:05 +0100] debug/HttpUtility: Request body: '{"author":"user","comment":"test","force":false,"host":"host.tld"}'
[2023-02-05 15:35:05 +0100] notice/ApiActionHandler: Running action send-custom-notification
[2023-02-05 15:35:05 +0100] information/Checkable: Checkable 'host.tld' has 1 notification(s). Checking filters for type 'Custom', sends will be logged.
[2023-02-05 15:35:05 +0100] notice/ApiListener: Relaying 'event::SendNotifications' message
[2023-02-05 15:35:05 +0100] notice/Notification: Attempting to send notifications of type 'Custom' for notification object 'host.tld!jabber-host'.
[2023-02-05 15:35:05 +0100] debug/Notification: Type 'Custom', TypeFilter: Acknowledgement, Custom, DowntimeEnd, DowntimeRemoved, DowntimeStart, FlappingEnd, FlappingStart, Problem and Recovery (FType=8, TypeFilter=-1)
[2023-02-05 15:35:05 +0100] notice/ApiListener: Relaying 'event::SetForceNextNotification' message
[2023-02-05 15:35:05 +0100] debug/Notification: User 'user' notification 'host.tld!jabber-host', Type 'Custom', TypeFilter: Acknowledgement, Custom, DowntimeEnd, DowntimeRemoved, DowntimeStart, FlappingEnd, FlappingStart, Problem and Recovery (FType=8, TypeFilter=-1)
[2023-02-05 15:35:05 +0100] debug/Notification: User 'user' notification 'host.tld!jabber-host', State 'Up', StateFilter: Critical, Down, OK, Unknown, Up and Warning (FState=16, StateFilter=-1)
[2023-02-05 15:35:05 +0100] information/Notification: Sending 'Custom' notification 'host.tld!jabber-host' for user 'user'
[2023-02-05 15:35:05 +0100] warning/PluginUtility: Error: Non-optional macro 'notification_output' used in argument '-O' is missing.
[2023-02-05 15:35:05 +0100] information/HttpServerConnection: Request: POST /v1/actions/send-custom-notification (from [::ffff:127.0.0.1]:60712), user: icingaweb2, agent: GuzzleHttp/6.5.5 curl/7.74.0 PHP/7.4.33, status: OK).
[2023-02-05 15:35:05 +0100] notice/ApiListener: Relaying 'event::NotificationSentToAllUsers' message
[2023-02-05 15:35:05 +0100] warning/PluginNotificationTask: Notification command for object 'host.tld' (PID: -1, arguments: 'sh' '-c' '') terminated with exit code 3, output: Error: Non-optional macro 'notification_output' used in argument '-O' is missing.
[2023-02-05 15:35:05 +0100] information/Notification: Completed sending 'Custom' notification 'host.tld!jabber-host' for checkable 'host.tld' and user 'user' using command 'jabber-host'.
[2023-02-05 15:35:05 +0100] notice/ApiListener: Relaying 'event::NotificationSentUser' message
[2023-02-05 15:35:05 +0100] information/HttpServerConnection: HTTP client disconnected (from [::ffff:127.0.0.1]:60712)
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